Such a fixing device may in particular be used on a man-made satellite so as to secure to the satellite a silica or glass mirror whose weight may be up to about 20 kg. In fact, between its conditions of use in space and on the ground, such a mirror is subjected to temperatures which may vary between -269.degree. C. and +180.degree. C. Moreover, it is required to withstand significant vibrations and accelerations, especially during the launching phase, without sustaining any degradations or deformations and in particular of its active surface.
Amongst the currently known devices for securing a fragile object, such as a mirror, none of these fully satisfy these various requirements.
Accordingly, the known technique, for example, consisting of glueing blocks flush with the substrate of the mirror, which does not exhibit or hardly exhibits any drawback within a range of temperatures of less than 40.degree. C., may result in the glue film or the substrate rupturing during extremely large temperature ranges owing to the stresses generated in the substrate of the mirror by differential expansions.